List Feature Classes and use Update Cursor to calculate date values

Question

The basic premise is as follows: look in a folder and find all feature classes (within file GDBs), use a for loop to isolate feature classes one at a time and subsequently isolate date attributes, iterate through and update all the date-related attributes to a given value (currently set at 9/9/9999).

The code will run, but nothing happens. The print statements I have embedded won't even return anytihng. I think the error is somewhere up at the beginning.

import arcpy
import os
try:
 def fcs_in_workspace(workspace):
 arcpy.env.workspace = workspace
 for fc in arcpy.ListFeatureClasses():
 yield os.path.join(workspace, fc)
 for ws in arcpy.ListWorkspaces():
 for fc in fcs_in_workspace(os.path.join(workspace, ws)):
 yield fc
 for fc in fcs_in_workspace("path to folder of GDBs"):
 allFields = arcpy.ListFields(fc)
 stringFields = []
 for field in allFields:
 if field.type == "Date" and "flex" not in field.name:
 stringFields.append(field.name)
 print(str(field.name))
 stringCount = len(stringFields)
 with arcpy.da.UpdateCursor(fc, stringFields) as curU:
 for row in curU:
 rowU = row
 for fields in range(stringCount):
 # change below to None or ''
 if rowU[fields] == '':
 rowU[fields] = "9/9/9999"
 elif rowU[fields] == None:
 rowU[fields] = "9/9/9999"
 curU.updateRow(rowU)
 del curU
 print("Updated Dates for " + str(fc))
except Exception as e:
 print("Error: " + e.args[0])

• mikewatt: If nothing's being printed then it's not entering the first for loop, meaning fcs_in_workspace() isn't yielding anything. Add some print statements in there, make sure the folder path you're passing in is valid, etc.
• Vince: There's a ton of reasons to use ISO 8601 formatting (e.g. "YYYY-MM-DD") for date strings ob xkcd reference
• PolyGeo: I recommend removing try/except statements while testing and whenever you present code here because they can mask otherwise useful error messages.

Answer 1

Here's my solution to the first part of your script. Maybe combining this with your UpdateCursor will help? I think you may be grabbing the fields wrong. Let me know if this works! If not, I can do some more debugging tomorrow. FYI the feature classes I was testing didn't have date fields, so I just called String fields instead, so you'll have to change that part of the script.

import arcpy
import os
try:
 workspace = arcpy.env.workspace = r"FOLDER"
 gdb_list = arcpy.ListWorkspaces("*", "FileGDB")
 fc_list = []
 allfields = []
 stringFields = []
 for dirpath, dirnames, datatypes in arcpy.da.Walk(workspace, datatype = "FeatureClass"):
 for i in datatypes:
 fc_list.append(os.path.join(dirpath, i))
 #print (fc_list)
 for feature in fc_list:
 field_list = arcpy.ListFields(feature)
 for field in field_list:
 #print(field.type)
 if field.type == "String":
 stringFields.append(field.name)
 print(stringFields)
except Exception as e:
 print(e)
 print(arcpy.GetMessages())